Electric discharge machining apparatus

Abstract

An electric discharge machine apparatus has a numeric control unit which can optimally set jumping conditions without forcing the user to perform any complicated setting operation. The numeric control unit calculates an optimal jumping velocity from a value indicating a machine-allowable load for the electric discharge machining apparatus, a machining area according to the electric discharge machining conditions, and a machining gap length computed from the electric discharge machining conditions. The machining area is computed by the ratio between the proceeding velocity in machining and a discharge pulse frequency. The machining gap length is computed according to the current value of a machining current pulse as well as to a voltage loaded to the machining gap.

What is claimed is: 
     
       1. An electric discharge machining apparatus for machining a work in a machining liquid by supplying pulse power to a gap between an electrode and the work each provided in the machining liquid; said electric discharge machining apparatus comprising: a machining area inputting section for inputting an area to be machined by opposing said electrode and said work to each other;   a machining gap length inputting section for inputting a machining gap length for machining; and   a jumping condition computing section for computing a jumping velocity during a jumping operation, said jumping operation enlarging a distance between said electrode and said work, said velocity being computed on the basis of a value indicating a prespecified machine-allowable load for the electric discharge machining apparatus, a machining area inputted by said machining area inputting section, and a machining gap length inputted by said machining gap length inputting section.   
     
     
       2. An electric discharge machining apparatus according to claim 1, comprising; a driving load detector for detecting a driving load for a shaft-driving actuator in the electric discharge machining apparatus; wherein a driving load detected by said driving load detector is inputted to said jumping condition computing section to correct a jumping velocity computed by said jumping condition computing section. 
     
     
       3. An electric discharge machining apparatus for machining a work in a machining liquid by supplying pulse power to a gap between an electrode and the work each provided in the machining liquid; said electric discharge machining apparatus comprising: a machining area computing section for computing an area to be machined by opposing said electrode and said work to each other according to electric discharge machining conditions;   a machining gap length computing section for computing a machining gap for machining according to the electric discharge machining conditions; and   a jumping condition computing section for computing a jumping velocity in a jumping operation, jumping operation enlarging the distance between said electrode and said work, said velocity being computed on the basis of a value indicating a prespecified machine-allowable load for the electric discharge machining apparatus, a machining area computed by said machining area computing section, and a machining gap length computed by said machining gap length computing section.   
     
     
       4. An electric discharge machining apparatus according to claim 3, comprising; a driving load detector for detecting a driving load for a shaft-driving actuator in the electric discharge machining apparatus; wherein a driving load detected by said driving load detector is inputted to said jumping condition computing section to correct a jumping velocity computed by said jumping condition computing section. 
     
     
       5. An electric discharge machining apparatus according to claim 3; wherein said machining gap length computing section computes a machining gap length according to a current value of a machining current pulse as well as a voltage load at said machining gap. 
     
     
       6. An electric discharge machining apparatus according to claim 3; wherein said machining area computing section computes a machining area according to a ratio between a machining velocity and a discharge pulse frequency contributing to the machining. 
     
     
       7. An electric discharge machining apparatus according to claim 6, comprising a driving load detector for detecting a driving load for a shaft-driving actuator in the electric discharge machining apparatus; wherein a driving load detected by said driving load detector is inputted to said jumping condition computing section to correct a jumping velocity computed by said jumping condition computing section. 
     
     
       8. An electric discharge machining apparatus according to claim 6; wherein said machining gap length computing section computes a machining gap length according to a current value of a machining current pulse as well as a voltage load at said machining gap. 
     
     
       9. An electric discharge machining apparatus according to claim 8, comprising; a driving load detector for detecting a driving load for a shaft-driving actuator in the electric discharge machining apparatus; wherein a driving load detected by said driving load detector is inputted to said jumping condition computing section to correct a jumping velocity computed by said jumping condition computing section.